Digital Commons Network^™

On The Structure Of Graphs With Few P4s, Luitpold Babel, Stephan Olariu

Computer Science Faculty Publications

We present new classes of graphs for which the isomorphism problem can be solved in polynomial time. These graphs are characterized by containing — in some local sense — only a small number of induced paths of length three. As it turns out, every such graph has a unique tree representation: the internal nodes correspond to three types of graph operations, while the leaves are basic graphs with a simple structure. The paper extends and generalizes known results about cographs, P₄-reducible graphs, and P₄-sparse graphs.

Buckets: Aggregative, Intelligent Agents For Publishing, Michael L. Nelson, Kurt Maly, Stewart N. T. Shen, Mohammad Zubair

Computer Science Faculty Publications

Buckets are an aggregative, intelligent construct for publishing in digital libraries. The goal of research projects is to produce information. This information is often instantiated in several forms, differentiated by semantic types (report, software, video, datasets, etc.). A given semantic type can be further differentiated by syntactic representations as well (PostScript version, PDF version, Word version, etc.). Although the information was created together and subtle relationships can exist between them, different semantic instantiations are generally segregated along currently obsolete media boundaries. Reports are placed in report archives, software might go into a software archive, but most of the data and …

Creating A Canonical Scientific And Technical Information Classification System For Ncstrl+, Melissa E. Tiffany, Michael L. Nelson

Computer Science Faculty Publications

The purpose of this paper is to describe the new subject classification system for the NCSTRL+ project. NCSTRL+ is a canonical digital library (DL) based on the Networked Computer Science Technical Report Library (NCSTRL). The current NCSTRL+ classification system uses the NASA Scientific and Technical (STI) subject classifications, which has a bias towards the aerospace, aeronautics, and engineering disciplines. Examination of other scientific and technical information classification systems showed similar discipline-centric weaknesses. Traditional, library-oriented classification systems represented all disciplines, but were too generalized to serve the needs of a scientific and technically oriented digital library. Lack of a suitable existing …

A Fast Parallel Algorithm To Recognize P4-Sparse Graphs, Rong Lin, Stephan Olariu

Computer Science Faculty Publications

A number of problems in mobile computing, group-based collaboration, automated theorem proving, networking, scheduling, and cluster analysis suggested the study of graphs featuring certain “local density” characteristics. Typically, the notion of local density is equated with the absence of chordless paths of length three or more. Recently, a new metric for local density has been proposed, allowing a number of such induced paths to occur. More precisely, a graphG is called P4-sparse if no set of five vertices inG induces more than one chordless path of length three. P4-sparse graphs generalize the well-known class of cographs corresponding to …

Vector Geometry And Applications To Three-Dimensional Computer Graphics, Rory Morrison

Theses : Honours

The mathematics behind algorithms involved in generating three-dimensional images on a computer has stemmed from the analysis of the processes of sight and vision. These processes have been modeled to provide methods of visualising three-dimensional data sets. The applications of such visualisations are varied. This project will study some of the mathematics that IS used in three-dimensional graphics applications

Software Flexibility In A Web Environment, Michael Layng

Theses : Honours

Flexible software systems are designed to be able to adapt to changes in their environment without the need for programmer intervention. This allows companies and institutions to avoid the cost of hiring a programmer every time a business rule changes or a data structure is modified. The techniques of designing and implementing flexible 3GL software systems have been proven as a means of reducing the high cost of software maintenance caused by the changing of systems requirements. Such systems have been in operation in the European finance sector since the early 1980's. Edith Cowan University is participating in current research …

Good Software Development Processes Lead To Harmonious Project Teams Which In Turn Lead To Effective Project Performance, Rweyunga Kazaura

Theses : Honours

The modem world relies on computers in almost every facet of life. With the explosion of Information Technology, software development has become an important process. However, from the beginning, this process has suffered and continues to suffer from a number of problems. If these problems are not rectified, they can jeopardise projects and lead to project failure. Project failure results in a project being delivered: • without satisfying the functional and non-functional requirements requested by the user or customer • beyond the agreed schedule and/or • over budget. Research indicates that practising good software development processes (SDPs) can override these …

A Complex-Systems Perspective On The “Computation Vs. Dynamics” Debate In Cognitive Science, Melanie Mitchell

Computer Science Faculty Publications and Presentations

I review the purported opposition between computational and dynamical approaches in cognitive science. I argue that both computational and dynamical notions will be necessary for a full explanatory account of cognition, and give a perspective on how recent research in complex systems can lead to a much needed rapprochement between computational and dynamical styles of explanation.

Stackguard: Automatic Adaptive Detection And Prevention Of Buffer-Overflow Attacks, Crispin Cowan, Calton Pu, David Maier, Heather Hinton, Jonathan Walpole, Peat Bakke, Steve Beattie, Aaron Grier, Perry Wagle, Qian Zhang

Computer Science Faculty Publications and Presentations

This paper presents a systematic solution to the persistent problem of buffer overflow attacks. Buffer overflow attacks gained notoriety in 1988 as part of the Morris Worm incident on the Internet. While it is fairly simple to fix individual buffer overflow vulnerabilities, buffer overflow attacks continue to this day. Hundreds of attacks have been discovered, and while most of the obvious vulnerabilities have now been patched, more sophisticated buffer overflow attacks continue to emerge.

We describe StackGuard: a simple compiler technique that virtually eliminates buffer overflow vulnerabilities with only modest performance penalties. Privileged programs that are recompiled with the StackGuard …

An Interlibrary Loan System On The World Wide Web, Schubert Shou Boon Foo, Ee Peng Lim

Research Collection School Of Computing and Information Systems

Inter-Library Loan (ILL) service is one of the services provided by libraries that offers users a way to access library resources beyond their affiliated libraries. Additionally, it allows participating libraries to share and maximize their resources. This work examines the ILL process used by libraries in Singapore and proposes that the existing paper-based manual system be replaced by a Web-based ILL system. Such a Web-based system has been successfully designed and implemented at the Nanyang Technological University. The paper presents an overview of the system requirements and architecture, implementation details and demonstrates the feasibility and advantages of the new system.

An Integrated Web-Based Ill System For Singapore Libraries, Schubert Foo, Ee Peng Lim

Research Collection School Of Computing and Information Systems

The paper proposes an integrated Web-based inter-library loan (ILL) system to replace and enhance the existing manual-based ILL system used by Singapore libraries. It describes the system requirements that must be supported in order to make it a viable and acceptable solution to all participating libraries. Subsequently, it presents the client-server Web-based system architecture, database design and Java development platform that are used to implement the system. The new system exhibits a host of advantages over the manual system including the minimising of human resource by eliminating form-filling and other forms of paper work completely, improving the access and speed …

Parametric Software Project Estimating: An Analysis Of Current Practice, Stuart Hope

Theses: Doctorates and Masters

As society and the world economy moves into the second millennium. the service industries involving knowledge workers will continue to increase. Software is the enabling technology that is driving the knowledge industry. As the development of software is mostly a design process, where new artefacts are conceived and built, the prediction of outcomes in the process is fraught with difficulties. Software project estimating is one of the essential Software Engineering techniques that will enable the rationalisation of decision-making regarding software development. Estimates that are more accurate will increase the probability of success and lower the risk. This thesis analyses the …

Performing Cooperative Work And Conferencing On An Intranet Using Java, Thaveeporn Limpanyalers

Theses: Doctorates and Masters

The process of organising, preparing and conducting a meeting is a time consuming one. Additionally, geographic separation compounds the amount of effort required. Within this study, an electronic conferencing system in an Intranet environment is designed and implemented, thus enabling employees in the same organisation to meet up electronically without the dual constraints of time and space. Specifically, the study investigates incorporation of facial expressions and an ongoing polling system. The results demonstrate that a presence of facial expressions helps users to better engage in on-line discussion and that users find an ongoing poll to be useful in determining direction …

Network Security: An Evaluation Of Security Policies And Firewall Implementations, Melanie L. Abbas

Dissertations and Theses @ UNI

This paper begins focusing on network security issues. The areas of physical security, access security, and connection security are explored. Connection security provides the biggest need for improvement in the entire security field. This type of security is managed best with firewall implementations. Various firewall models are discussed.

Software evaluations were performed on three different commercial Internet security tools. The software was compared on the basis of ease of installation, functionality, level of security provided, and output available. In summary, the value of the firewall is dependent on the need to implement a firewall in an organization.

However, a security …

Requirement Elicitation For Environmental Life Cycle Processes, Mariam Y. Burmawalla

Theses

To develop a user-satisfying product the most essential ingredient is to understand user's needs and expectations from the system. Lack of communication between the user and the developer results in an unsatifying output from the user's point of view. Thus proper understanding between the stakeholder and the developer is the most important requirement during the development of any system.

Requirement elicitation process is one such means of expressing wants and requirements from the system by both the parties. Based on Software Engineering Institute's model, requirement elicitation is a web-based application that allows all the people involved in the system to …

Evaluation Of Information Modeling Methods: A Review, Keng Siau, Matti Rossi

Research Collection School Of Computing and Information Systems

Hundreds of modeling methods are in existence today. Yet practitioners and researchers are zealously "producing" new modeling methods. The "blooming" of modeling methods is not the problem; the lack of standardize techniques for evaluating them is. To further complicate the matter, most of the modeling methods are introduced based on common sense and intuition. Theoretical foundations and empirical evidence are severely lacking. With the current state of affairs, evaluation of modeling methods has become necessary. Comparing modeling methods provides us with the necessary knowledge and understanding on the strengths and weaknesses of each method. This knowledge can also guide us …

Automatic Flowchart Displays For Software Visualisation, Paul R. Schurmann

Theses: Doctorates and Masters

Understanding large software projects and maintaining them can be a time consuming process. For instance, when changes are made to source code, corresponding changes have to be made to any related documentation. One large section of the documentation process is the creation and management of diagrams. Currently there are very few automated diagramming systems that can produce diagrams from source code, and the majority of these diagramming systems require a significant amount of time to generate diagrams. This research aims at investigating the process of creating flowchart diagrams from source code and how this process can be fully automated. Automating …

Studies Of Quantum Chromodynamics With The Aleph Detector, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

No abstract provided.

An Upper Limit On The Τ Neutrino Mass From Three- And Five-Prong Tau Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A bound on the tau neutrino mass is established using the data collected from 1991 to 1995 at s√≃mZ with the ALEPH detector. Two separate limits are derived by fitting the distribution of visible energy vs invariant mass in τ−→2π−π+ντ and τ−→3π−2π+(π0)ντ decays. The two results are combined to obtain a 95% confidence level upper limit of 18.2 MeV/c2 on the mass of the tau neutrino.

Observation Of Doubly-Charmed B Decays At Lep, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A search for doubly-charmed B decays with both charmed mesons reconstructed is performed, using about 3.8 million hadronic Z decays recorded with the ALEPH detector at LEP. A clear signal is observed in the channels B→DsD¯(X)B→DsD¯(X) and B→DD¯(X)B→DD¯(X) (where D can be either a D00, a D++ or a D∗+∗+), providing the first direct evidence for doubly-charmed B decays involving no DsDs production. Evidence for associated K0SKS0 and K±K± production in the decays B→DD¯(X)B→DD¯(X) is also presented and some candidates for completely reconstructed decays B→DsD¯(nπ)B→DsD¯(nπ), B→DD¯K0SB→DD¯KS0 and B→DD¯K±B→DD¯K± are observed. Furthermore, candidates for the two-body Cabibbo suppressed decays B0→D∗−D∗+B0→D∗−D∗+ and …

Module Embedding, Atanas Radenski

Mathematics, Physics, and Computer Science Faculty Articles and Research

This paper proposes a code reuse mechanism called module embedding that enables the building of new modules from existing ones through inheritance, overriding of procedures, and overriding of types; the paper also describes an implementation scheme for this mechanism. Module embedding is beneficial when modules and classes are used in combination and need to be extended together, or when modules are more appropriate medium than classes.

Learning To See Analogies: A Connectionist Exploration, Douglas S. Blank

Computer Science Faculty Research and Scholarship

The goal of this dissertation is to integrate learning and analogy-making. Although learning and analogy-making both have long histories as active areas of research in cognitive science, not enough attention has been given to the ways in which they may interact. To that end, this project focuses on developing a computer program, called Analogator, that learns to make analogies by seeing examples of many different analogy problems and their solutions. That is, it learns to make analogies by analogy. This approach stands in contrast to most existing computational models of analogy in which particular analogical mechanisms are assumed a priori …

Bias And The Probability Of Generalization, Tony R. Martinez, D. Randall Wilson

Faculty Publications

In order to be useful, a learning algorithm must be able to generalize well when faced with inputs not previously presented to the system. A bias is necessary for any generalization, and as shown by several researchers in recent years, no bias can lead to strictly better generalization than any other when summed over all possible functions or applications. This paper provides examples to illustrate this fact, but also explains how a bias or learning algorithm can be “better” than another in practice when the probability of the occurrence of functions is taken into account. It shows how domain knowledge …

Ta Da! - The Text Adventure Design Assistant A Visual Tool For The Development Of Adventure Games, Sean Molley

Masters Theses & Specialist Projects

In this paper, I survey past and present tools available to text adventure game authors, and then describe a new product: the Text Adventure Design Assistant (TA DA!), a visual programming system for creating text adventure games. My system consists of two parts: an abstract framework which defines an archetypical game, and a user interface which allows for the construction of games in a visual manner by manipulating the elements of the abstract game to produce a concrete design. The two most popular contemporary programming languages for creating text adventure games, TADS and Inform, are compared and contrasted, and my …

Corrigendum To “Post-Surgical Passive Response Of Local Environment To Primary Tumor Removal”: Mathl. Comput. Modelling, Vol. 25, No. 6, Pp. 7–17, 1997, J. A. Adam, C. Bellomo

Mathematics & Statistics Faculty Publications

The computer program that was used to generate the graphs for the concentration of inhibitor contained an error. This influenced the scaling in the original Figures 2 and 3. As an example, a sample of the corrected graphs are given below. Copies of other corrected figures can be obtained from the authors. It is important to note that the “pulse” appears for the function rC(r, t). As can be seen, it travels slowly outward with decreasing amplitude. The mathematical analysis in the paper remains unchanged.

An Incompleteness Handling Methodology For Validation Of Bayesian Knowledge Bases, David J. Bawcom

Theses and Dissertations

The PESKI (Probabilities, Expert Systems, Knowledge, and Inference) system attempts to address some of the problems in expert system design through the use of the Bayesian Knowledge Base (BKB) representation. Knowledge gathered from a domain expert is placed into this framework and inferencing is performed over it. However, by the nature of BKBs, not all knowledge is incorporated, i.e. the representation need not be a complete representation of all combinations and possibilities of the knowledge, as this would be impractical in many real-world systems. Therefore, inherent in such a system is the problem of incomplete knowledge, or spaces within the …

Visualization And Animation Of A Missile/Target Encounter, Jeffrey T. Bush

Theses and Dissertations

Existing missile/target encounter modeling and simulation systems focus on improving probability of kill models. Little research has been done to visualize these encounters. These systems can be made more useful to the engineers by incorporating current computer graphics technology for visualizing and animating the encounter. Our research has been to develop a graphical simulation package for visualizing both endgame and full fly-out encounters. Endgame visualization includes showing the interaction of a missile, its fuze cone proximity sensors, and its target during the final fraction of a second of the missile/target encounter. Additionally, this system displays dynamic effects such as the …

The Effect Of Data Model, System And Task Characteristics On User Query Performance – An Empirical Study, Hock Chan, Keng Siau, Kwok-Kee Wei

Research Collection School Of Computing and Information Systems

With the proliferation of end-user computing and empowerment of end users in the organizations, the user-database interface is increasingly being recognized as an important research area. A user-database interface consists of two key components: the data model and the query language. Database management system designers can manipulate these two components to produce an effective database interface to maximize user task performance. However, in order to do this, the designers first need to know the effect of the two components on end users and the interaction effect of the two components. Despite the acknowledgment of user-database interface as a cornerstone in …

Inclusive Production Of Neutral Pions In Hadronic Z Decays, R. Barate, M. Thulasidas

Research Collection School Of Computing and Information Systems

A measurement of the inclusive production of π0 mesons in hadronic Z decays is presented and compared to Monte Carlo model predictions. The analysis is based on approximately 2 million hadronic events recorded with the ALEPH detector at LEP at a centre-of-mass energy of ⊡s = 91.2 GeV. Neutral pions are reconstructed using photons measured in the electromagnetic calorimeter and photons from conversion pairs. The inclusive π0 momentum spectrum is measured in the range 0.025 x p = p/p beam 0 per hadronic Z is found to be 4.80 ± 0.07(stat) ± 0.31(sys). The differential inclusive π0 cross section is …

Interactive Visualization Of Multi- Dimensional Scientific Data (Ph.D. Thesis), Daniel R. Schikore

Department of Computer Science Technical Reports

No abstract provided.